Scientists primarily work with two kinds of stem cells from animals and humans, respectively “embryonic stem cells” and non-embryonic “somatic” or “adult stem cells”. There is a third category called “induced pluripotent stem cells” that can be generated under special conditions, which allow some specialized adult cells to be “reprogrammed” genetically to assume a stem cell-like state.
Medical researchers believe that stem cell therapy has the potential to dramatically change the treatment of human disease. A number of adult stem cell therapies already exist, particularly bone marrow transplants that are used to treat leukemia. It is anticipated that in the future, stem cell will be used to treat a wider variety of diseases including cancer, Parkinson's disease, spinal cord injuries, Amyotrophic lateral sclerosis, multiple sclerosis, muscle and bone damage, vision and hearing loss, and diabetes, amongst a number of other impairments and conditions. Scientists are already using stem cells in the laboratory to screen new drugs and to develop model systems to study normal growth and identify the causes of birth defects. Finally, research on stem cells continues to advance knowledge about how an organism develops from a single cell and how healthy cells replace damaged cells in adult organisms.
The adult stem cells have less legal, humanitarian and body rejection hurdles, when compared with embryonic stem cells, which makes them more attractive for the stem cells treatments. Unfortunately, there are reduced numbers of stem cells viable for multiplication and differentiation, when compared to the embryonic stem cells. There is therefore a need for stem cell harvesting to be made more efficient, including maximizing the number of cells harvested from one site. There is a further need for improving the efficiency and potentially successful outcome in post-harvest stem cell treatment steps, such as proliferation of viable stem cells sufficient for tissue generation, differentiation to desired cell types, maintaining survival of the cells in a transplant recipient, and integrating with desired tissue and with proper function in a recipient.